Survivor: Nicaragua is the twenty-first season of the American CBS competitive reality television series Survivor. It premiered on September 15, 2010 at 8 pm, moving to the Wednesday timeslot for the first time since Survivor: Borneo.

Old vs. Young: The 20 contestants will be divided up into two tribes based on their ages. The Espada tribe will feature contestants over the age of 40, and the La Flor tribe will include contestants aged 30 years and younger. The producers deemed that they have a good slate of competitive older people, so they expected that the 'Battle of the Ages' format will not agree to the younger tribe's sheer strength.

Hidden Immunity Idol: Similar to Fiji, China, Tocantins, Samoa and Heroes vs.Villains, one Idol will be hidden at both tribe camps. Jeff Probst, has also announced that the Hidden Immunity Idol will be hidden differently this season. Realizing that Idols have been found too easily the past two seasons (notoriously often by Russell Hantz), the clues of the Idol's location will be rebus puzzles rather than textual. They dubbed it as "The Russell Factor." Both Idols are usable up until the Day 36 Tribal Council.

Medallion of Power : The two tribes will also vie for a new item, the Medallion of Power. The tribe that currently hold the Medallion will have an option to have an advantage in challenges (i.e. shortcuts, less workload etc.). They can either use it or save it until the next challenge. But once they used it, regardless of whether the host tribe won or lost the challenge, they must surrender it to the rival tribe. The premise of the Medallions is to further even up the playing field for the tribes defined by age. After the tribe switch, the Medallion was retired.

Challenges: Aside from the Medallion of Power, challenges in this season will be more innovative and less physical, due to the Old vs. Young format. Instead of sheer strength, majority of the challenges will require teamwork to win. Jeff Probst said: "It's way less physical this season, so there will be no wrestling on the beach. Our challenge department has come up with some inventive ideas that are fair, still take skill and still take strategy. They're going to be the kind of things you think would be fun to do."

Tribe Switch: Selected tribe members will be transferred to the rival tribe.

Twenty new castaways were divided into tribes by age: La Flor, which consisted of castaways 30 and younger, and Espada, which consisted of castaways 40 and older. Both tribes also vied for ownership of the newly introduced Medallion of Power, which granted them an advantage when played in challenges. At Espada, several members of the tribe vied for leadership. While Jimmy Johnson initially took control, he was quickly overthrown by Marty Piombo and voted out. Marty furthered his control of the tribe by finding the Hidden Immunity Idol and voting out aspiring leader Jimmy Tarantino.

Despite dominating in challenges, La Flor also had their own share of conflicts. Two warring alliances (one led by Shannon Elkins, and the other led by Brenda Lowe and Sash Lenahan) emerged, with both alliances vying for Chase Rice's vote. A confused Shannon lashed out at Tribal Council, making some of his alliance members and Chase to turn on him, causing his elimination instead. The remnants of Shannon's group found themselves at the mercy of the majority alliance. Not only did they have the numbers, but Brenda and NaOnka Mixon successfully found their Hidden Immunity Idol, leaving them more vulnerable. However, their supposed eliminations were put on hold, as La Flor went on to win two more Immunity Challenges.

A Day 12 Tribe Switch caused allegiances to shift. At the new Espada, Holly Hoffman bonded with her new tribemates, and formed an alliance with them, causing Tyrone Davis and Yve Rojas' eliminations. At the new La Flor, the once-powerful Marty fell from grace, thanks to Jane Bright flipping to Brenda's alliance. Not only did Marty get blackmailed by Sash into giving up his Immunity Idol, but he also became witness to the ouster of his closest ally, Jill Behm. On Day 19, the two tribes were merged into the Libertad tribe.

Sash and Brenda took control of Libertad, persuading the rest of the tribe to eliminate Alina Wilson and Marty. Seeing that Brenda was controlling the game, Holly made her move by turning everybody else on Brenda (who hoped that Sash would give her his Idol), causing her demise. Brenda's elimination, along with the voluntary exits of Kelly Shinn and NaOnka, left Sash alone and without allies. However, Sash managed to find a new alliance in Holly, Chase, and Jane.

After voting out the untrustworthy Benry Henry, the new formed majority alliance planned to eliminate Fabio Birza next, but he went on to win individual immunity. While Dan Lembo was the only non-immune member of the minority alliance, Chase, Holly and Sash decided to turn on Jury threat Jane, and voted her out instead. The next day, Fabio won immunity again and Dan was voted out. However, after Fabio won his third successive Immunity Challenge, Chase and Sash decided to turn on Holly, whom they thought had the best chance to win the game against them.

At the Final Tribal Council, Sash was ignored by the Jury because of his numerous deceptions; while Chase was castigated for his indecisiveness at several points during the game. Fabio on the other hand was chastised by the other two for seemingly coasting throughout the game, but he rebutted that he did that on purpose to not hurt anybody's feelings, and still stay longer in the game. In the end, Fabio's unconventional strategy earned him the title of Sole Survivor by a 5-4-0 vote.

^1 Combined Reward/Immunity Challenge.^2 Jeff bribed the winners of the Reward Challenge, that if one of them gives up his/her reward, the tribe will be given a new supply of rice and tarp. Furthermore, being singled out due to the odd number of players, Dan was chosen to sit out in the challenge, but if he guessed the winning team correctly, he would join them at their reward. Dan guessed the winning team correctly, winning himself reward as well.^3 Sash used a Hidden Immunity Idol, negating 1 vote against him.

In Episode 6, Tribal Council resulted in a tie. Per the rules, a second vote was held where the castaways involved in the tie would not vote and the remaining castaways could only vote for the two tied.

In Episode 12, Kelly S. and NaOnka both elected to quit the game. No vote occurred for their removal.

In Episode 14, Sash used a Hidden Immunity Idol, therefore any votes cast against him were nullified.

This season marked the return of the Tribe Switch, which was absent in the past three seasons.

This season marked the seventh and eighth time that a contestant opted to voluntarily leave the competition. But this is the first time in the history of the series that two people quit at the same time.

This season marked the second time that Jeff bribed a tribe for something after an unfortunate event at camp. The first time this happened was in Survivor: The Australian Outback, where the Barramundi tribe suffered miserably after a terrible storm, with their remaining food supply being washed up. Jeff bribed them to dismantle their shelter for a new supply of rice.

This is the first time since Survivor: Tocantins that there have been all-male finalists, though this is the first time that the final three entirely comprised of male contestants, namely, Sash, Chase and Fabio.

This is the fourth consecutive season that all finalists came from one original tribe.

This is the first time since Survivor: The Amazon that the contestants' torches were designed with their tribe affiliations in mind. Original La Flor members had an etched flower design at their torches, while the original Espada had saber-like etchings on theirs.

This was the first time that tribe names were prominently displayed on the buffs, though this would be the second time that buffs were customized for a tribe, following Survivor: All-Stars, where their buffs had their tribe insignia drawn on it.

This is the first season since Survivor: Gabon where the difference in the jury vote was only one vote.

It is the first season since Survivor: Cook Islands where the jury vote has been 5-4-0. There had been three seasons with a final three and nine jury members between Cook Islands and Nicaragua.

This is the second season in a row where the oldest contestant gets 18th place.

This was the first season since Survivor: All-Stars to feature two castaways quit in the same season. However, unlike the former season, the two contestants quit in the same episode.

This is currently the only season where the Final Three is entirely male.

This is the first season to have a castaway that was born in the 1990s

Composer Russ Landau had composed a new version of "Ancient Voices" for this season featuring indigenous flutes and elements of Spanish music, however the producers instead used an extended version of the original theme from season 1. The theme composed for Survivor: Nicaragua was later released on iTunes and is known as "Survivor: Nicaragua Unapproved."